On December 6, 2001, Nicaragua instituted proceedings against Colombia before the ICJ in respect of a dispute comprising âa group of related legal issues subsistingâ between the two countries âconcerning title to territory and maritime delimitationâ in the western Caribbean. Colombia contested the ICJâs jurisdiction.

Under international law, a state with sovereignty over an island, whatever its size, is entitled to claim a 12-nautical-mile territorial sea and other maritime areas around it. Accordingly, in order to draw the maritime boundary between the two countries in the disputed area, the ICJ first had to determine which state had sovereignty over seven contested islands at Alburquerque Cays, Bajo Nuevo, East-Southeast Cays, QuitasueÃ±o, Roncador, Serrana, and Serranilla.[3]

The ICJ also found that the available colonial-era evidence afforded inadequate assistance in determining sovereignty over the disputed maritime features on the basis of uti possidetis at the time of the partiesâ independence from Spain.

Given that Colombia is not a party to the United Nations Convention on the Law of the Sea (âUNCLOSâ), the applicable law in this case was customary international law, as reflected in UNCLOSâ Articles 74 (EEZ delimitation), 83 (continental shelf delimitation), and 121 (islands), and the decisions of international courts and tribunals.

The ICJ recalled that, in effecting a maritime delimitation involving overlapping zone entitlements, courts and tribunals normally employ a multi-stage methodology. After identifying the relevant coasts with a view to determining the partiesâ overlapping claims and the relevant area within which the delimitation is to be effected, a provisional delimitation line is established, usually an equidistance/median line, by reference to appropriate base points (Stage 1). The provisionally constructed line is then examined in the light of equitable factors, called ârelevant circumstances,â to determine whether it is necessary to adjust or shift that line in order to achieve an equitable result (Stage 2). The last stage in the delimitation involves the application of a final proportionality check to verify the equitableness of the tentative delimitation and to ensure that the ultimate result is not tainted by some form of gross disproportion (Stage 3).[8]

The parties advanced differing versions of the relevant coasts for purposes of drawing the provisional line. The ICJ concluded that the entire mainland coast of Nicaragua, with a length of some 531 kilometers, constituted the relevant Nicaraguan coast, while the relevant Colombian coast was confined to the coasts of the islands under Colombian sovereignty, measuring 65 kilometersâresulting in a ratio of approximately 1:8.2 in favor of Nicaragua. In determining the relevant coasts, the ICJ disregarded Bajo Nuevo, QuitasueÃ±o, and Serranilla. As regards the extent of the relevant area in which it was to effect the delimitation, the Court essentially adopted Nicaraguaâs version, which, at just over 200,000 square kilometers, is at least one-third larger than the area advocated by Colombia.[9]

Rejecting Nicaraguaâs enclave approach, the ICJ confirmed that under international law Colombia may claim a 12-nautical-mile breadth of territorial sea for each Colombian island within the relevant area. With regard to the overlap between Colombiaâs territorial sea entitlement derived from each island and Nicaraguaâs entitlement to a continental shelf and EEZ, the Court found that delimitation of this area, involving opposite coasts, could be satisfactorily accomplished by constructing a provisional median line, except that no base points should be placed on QuitasueÃ±o, Serrana, and Low Cay due to their small size.

The ICJ rejected Colombiaâs argument that no adjustment or shifting of the provisional median line was required in this case, finding instead that the substantial disparity in the lengths of the partiesâ relevant coasts, combined with the cut-off effect caused by a few islands denying Nicaragua access to the sea-bed and waters to their east (affecting three quarters of the area into which Nicaraguaâs coast projects), made strict application of the equidistance method inappropriate in the present case.

The Court further determined that, from the extreme northern and southern points of that line, the boundary follows the pertinent parallels of latitude until reaching the 200-nautical-mile limit from the baselines from which the territorial sea of Nicaragua is measured, with the first part of the southern line running along 12-nautical-mile envelopes of arcs around the islands situated in that area.

With regard to QuitasueÃ±o and Serrana islands, situated north of the northern limit of the line, the ICJ considered that the use of enclaves achieved the most equitable solution and fixed a boundary tracing 12-nautical-mile envelopes of arcs.

Finally, the ICJ determined that the line drawn by it did not entail such a disproportionality as to create an inequitable result.[10]

While the Courtâs judgment, rendered in the longest-running territorial and maritime delimitation case in ICJ history, confirms Colombiaâs sovereignty over disputed islands in the western Caribbean and does not attribute to Nicaragua the whole of the area it had claimed, in the aftermath of the ruling, Nicaragua expressed greater satisfaction over the boundary fixed by the ICJ than Colombia. This may be explained by the natural resources that are believed to be present in the maritime zones over which Nicaragua henceforth will be exercising rights. Notwithstanding the fact that ICJ judgments are binding and not subject to appeal, Colombia has announced that it will explore ways to overturn it.[11] On November 27, 2012, Colombia informed the Organization of American States of its decision to withdraw from the 1948 Pact of Bogota, thereby preventing future disputes involving Colombia from being brought before the ICJ on the basis of that treaty.

Maritime boundary cases are often triggered by competing claims to natural resources. The Courtâs ruling affirms the cautious treatment that international courts and tribunals have given to resource-related criteria when considering relevant circumstances, indicating that any issues of access to natural resources will be ignored unless they are âso exceptional as to warrant it treating them as a relevant consideration.â[12]

The Courtâs ruling is especially instructive regarding the determination of the status of islands, as opposed to low-tide elevations and other maritime features not capable of appropriation and of generating maritime entitlements.

It remains to be seen how this ruling will affect the authority of boundary lines, particularly pre-UNCLOS lines, established in existing instruments, especially in the context of the pending maritime delimitation case between Chile and Peru in which the ICJ will soon be issuing its decision. Will such lines, which often constitute simple parallel of latitude lines, as in the case of Chile-Peru, be recognized as de jure maritime boundaries, or are they merely territorial allocation lines open to re-drawing by international courts and tribunals having competent jurisdiction?

The ICJ ruling comes on the heels of the first maritime delimitation decision issued by the International Tribunal for the Law of the Sea (âITLOSâ), established under UNCLOS. On March 14, 2012, ITLOS fixed a single maritime boundary between Bangladesh and Myanmar, representing an adjusted equidistance line in the EEZs and continental shelves appertaining to Bangladesh and Myanmar, respectively.[13]The ITLOS case lasted only twenty-seven months.

About the Author:

Pieter H.F. Bekker, LL.M., Ph.D. (Intâl Law), an ASIL member, holds the Chair in International Law at the University of Dundeeâs Centre for Energy, Petroleum and Mineral Law and Policy (âCEPMLPâ) and is a Partner at Steptoe & Johnson LLP in Brussels (p.bekker@dundee.ac.uk). A former staff lawyer in the ICJ Registry and member of the New York Bar, he has appeared as counsel in several ICJ cases. Prof. Bekker has written or edited two books (Commentaries on World Court Decisions (1987-1996) (1998) and World Court Decisions at the Turn of the Millennium (1997-2001) (2002)) and numerous articles and notes on the ICJ. The views expressed herein are solely those of the author.

[3] Both countries agreed that, with one exception, all disputed maritime features remain above water at high tide and thus, as islands, are capable of appropriation. With regard to the bank of QuitasueÃ±o, the ICJ found that only one of fifty-four features identified by Nicaragua within that bank constitutes an island, the others being low-tide elevations that do not generate maritime entitlements.

[6] The ICJ declined to delimit the âextendedâ continental shelf beyond 200 nautical miles, as requested by Nicaragua, because the authority to delineate the outer limits of continental shelf is vested in the Commission on the Limits of the Continental Shelf under UNCLOS, to which Nicaragua is a party, and the preliminary information submitted by Nicaragua under UNCLOS did not establish that it has a continental margin extending far enough to overlap with Colombiaâs 200-nautical-mile entitlement to the continental shelf. Seeid. Â¶Â¶ 113â31.

[7] A median line is a line every point of which is equidistant from the nearest points on the baselines from which the breadth of the territorial seas of the disputing states is measured.

Copyright by The American Society of International Law

The purpose of ASIL Insights is to provide concise, objective, and timely background for recent developments of interest to the international community. The American Society of International Law does not take positions on substantive issues, including the ones discussed in ASIL Insights. Educational and news media copying is permitted with due acknowledgement.